1. Field of the Invention
The invention herein disclosed relates generally to a curb inlet filter for storm drains. More particularly, to a curb inlet filter for filtering out debris and sediments and the like which is adapted to removably engage with such an inlet and prevent debris, soil, trash, and sediment from entering the storm drainage system where it can easily contaminate the shoreline.
2. Prior Art
Runoff, in the form of water from heavy rains or melted snow, in order to maintain streets in a driveable condition and to prevent flooding locally, is conventionally collected in a storm sewer system. Such systems generally collect runoff through grates in the street surface or through curb inlets which provide an aperture for runoff to flow into the storm drain sewer system.
In most municipalities in the United States and worldwide, the runoff water collected in the storm drain system has not been viewed as particularly hazardous to the health of humans and animals. Consequently, most storm drainage systems collect runoff and channel it directly into the ocean or a river. However, in recent years, it has been found that such runoff carries particulate and trash and other solids and dissolved solids along with it and into the body of water into which it exits. The result being that the nations's seashores, harbors and rivers have become polluted with trash, soil, particulate, leaves, bacteria and just about anything that might be carried by runoff water into the drains and the underlying storm sewer systems which collect this runoff.
Plastics are of special concern in that they easily float in the ocean or a stream and they are long lived since they are unaffected by weather and do not dissolve in water. Over time they collect on seashores and on the shores around other bodies of water that receive storm runoff. These plastics such as six-pack can restraints can be particularly hazardous to wildlife encountering them.
Another concern in recent years is that of silt and soil particulate which is collected by runoff water and deposited into storm drains suspended in the runoff water. Such material upon reaching the ocean, a lake or shallow bay, over time, settles to the bottom thereby raising the bottom of harbors, lake beds and river beds. Over time this can become hazardous to shipping traffic as well as personal water craft. Further, the storm drain system itself can become clogged or can be rendered inoperable if too much soil and silt enters the system during a large runoff period. Silt is especially a problem during the building of large homes and commercial building tracts. During the building process, with heavy grading, the soil becomes denuded and is easily washed away by runoff into the storm sewer system.
In the past, numerous products have been employed in attempts to prevent sediment, trash, and other solids from flowing into curb inlets during runoff periods where they are communicated to the storm sewer system. Products such as straw wattles have been used to filter out sediment and other solids flowing into a curb inlet storm drain by placing them in front of such inlets. Hay bails have also been used to filter out sediment and other solids from the runoff flowing into a curb inlet. Other attempts have used permanent grates, stones wrapped in chicken wire and fabric filters covering grates.
The straw wattle and hay bail type of sediment filters often get clogged and are rendered useless. Additionally, as they are made of organic material, they may decompose and slip into the storm drain system only to cause the clogging they are trying to prevent. Further, neither the straw, hay, or stone bundles wrapped in wire, filter out silt and fine soils which have particles small enough to move through them.
Metal filters and screens have also been tried without great success. Such filter systems generally are placed in a temporary fashion with weights or belts to hold them and are easily dislodged, stolen or removed by vandals who can see that they are only placed with weights or belts. Other metal and metallic screen filters are permanent in nature and as such are harder to install and remove which can be a major problem if they clog since they can cause flooding if not removed quickly.
As such, their exists an unmet need for a storm drain inlet filter that is easy to engage and disengage to filter incoming runoff to a storm drain inlet and remains engaged during high water flow. Such a device in order to dissuade vandals and theft should have the appearance of being permanently installed, yet should be easily removable and engageable to storm drain inlets of varying sizes to thereby filter such inlets. Such a device, once engaged, should serve to keep soil, sediment, silt, trash and solids, out of the storm water system. However, in keeping such materials out of the storm water system, such a device should also not require cleaning constantly which increases cost. Instead, it should be adapted to deflect such solid materials in the runoff, back into the street where street sweepers may later remove it. Finally, such a device, should be easily and securely engageable to a large variety of different sized storm drain inlets due to the wide variance in standard sizing of such and should do so without modification for each different size.